287935-43-7Relevant academic research and scientific papers
Palladium/PC-Phos-Catalyzed Enantioselective Arylation of General Sulfenate Anions: Scope and Synthetic Applications
Wang, Lei,Chen, Mingjie,Zhang, Peichao,Li, Wenbo,Zhang, Junliang
, p. 3467 - 3473 (2018/03/13)
Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides in good yields (up to 98%) with excellent enantioselectivities (up to 99% ee) by the use of our developed chiral O,P-ligands (PC-Phos). PC-Phos are easily prepared in short steps from inexpensive commercially available starting materials. The single-crystal structure of the PC4/PdCl2 showed that a rarely observed 11-membered ring was formed via the O,P-coordination with the palladium(II) center. The salient features of this method include general substrate scope, ease of scale-up, applicable to the late-stage modification of bioactive compounds, and the synthesis of a marketed medicine Sulindac.
Structural motifs in enantiopure halogenated aryl benzyl sulfoxides: Effect of fluorine substitution
Capozzi, Maria Annunziata M.,Capitelli, Francesco,Cardellicchio, Cosimo
, p. 5442 - 5451 (2015/01/09)
A series of enantiopure crystalline aryl benzyl sulfoxides, bearing different substituents on both the aryl groups, were synthesized by an enantioselective oxidation of the corresponding sulfides. Structural investigations, achieved by means of single-crystal X-ray diffraction, allowed us to recognize the main assembling interactions. The same procedure was repeated for some corresponding fluorinated aryl benzyl sulfoxides. The synthesis of the enantiomers of a new fluorinated compound, which shows unusual structural patterns, prompted us to compare the structural motifs of the two families of sulfoxides (fluorinated and unfluorinated) and to investigate the changes due to the fluorine substitution. Some short contacts involving the fluorine atom were discussed in more details, taking into account the recent interest in these sometimes controversial interactions. (Chemical Equation Presented).
Catalytic enantioselective oxidation of bulky alkyl aryl thioethers with H2O2 over titanium-salan catalysts
Bryliakov, Konstantin P.,Talsi, Evgenii P.
experimental part, p. 4693 - 4698 (2011/10/03)
A simple and efficient catalytic procedure for the oxidation of bulky (preferably aryl benzyl substituted) thioethers with hydrogen peroxide in good to high yields and enantioselectivities (up to 98.5%ee) is reported. The high optical yields are achieved in a tandem stereoconvergent enantioselective oxidation and kinetic resolution process. A reasonable balance between the sulfoxide yield and enantioselectivity could be found by varying the concentration and temperature. An improved synthesis of the titanium-salan catalysts for the preparation of a more stereoselective catalyst is reported.
Systematic investigation of CD spectra of aryl benzyl sulfoxides interpreted by means of TDDFT calculations
Pescitelli, Gennaro,Di Pietro, Sebastiano,Cardellicchio, Cosimo,Capozzi, Maria Annunziata M.,Di Bari, Lorenzo
experimental part, p. 1143 - 1154 (2010/04/02)
(Chemical Equation Presented) The CD spectra of 13 crystalline aryl benzyl sulfoxides 1a-m with various substituents on the two aromatic rings were recorded in solution and in the solid state. Solution CD spectra were very homogeneous along the series, consisting in most cases of a couplet-like feature in the 200-300 nm region. The red-shifted component of the couplet, corresponding to the sulfoxide-centered n-π* transition, is always positive for (R) absolute configuration in accordance with Mislow?s rule. The presence of a strong electron-withdrawing substituent on the phenyl ring (nitro or ester group) alters the shape of the CD spectrum. CD calculations using the TDDFT method were run for eight representative compounds using DFT-optimized geometries. In all cases, calculated spectra were in very good agreement with experimental ones and allowed for rationalization of the diverse spectral behaviors. It is demonstrated thatTDDFT//DFTcalculations represent a reliable option for assigning the absolute configuration of this class of compounds whenever crystals suitable for X-ray are not available. Solid-state CD spectra recorded with the KCl pellet technique were in some cases in agreement with those in solution. However, in other cases new and strongCD signals appeared which were interpreted as being due to intermolecular couplings in the crystals.
A combined theoretical and experimental investigation on the enantioselective oxidation of aryl benzyl sulfides in the presence of a chiral titanium catalyst
Naso, Francesco,Capozzi, Maria Annunziata M.,Bottoni, Andrea,Calvaresi, Matteo,Bertolasi, Valerio,Capitellil, Francesco,Cardellicchio, Cosimo
supporting information; experimental part, p. 13417 - 13426 (2010/06/16)
An experimental investigation of the enantioselective oxidation of aryl benzyl sulfides by tert-butyl hydroperoxide in the presence of a titanium/hydrobenzoin catalyst has shown that these sulfides are ideal substrates for this catalytic system, with negl
